Physiological responses to a cold, wet and windy environment during
prolonged intermittent walking.
Weller, A. S., C. E. Millard, M. A. Stroud, P. L. Greenhaff, and I. A.
Macdonald.
Department of Physiology and Pharmacology, University of Nottingham
Medical School, Queen's Medical Centre, Nottingham NG7 2UH, U.K.
APStracts 3:0257R, 1996.
The potentially deleterious influence of body cooling on the
thermoregulatory and metabolic responses to prolonged walking
exercise has not been established. To address this problem, 10 men
completed a 6 hour intermittent (15 min rest, 45 min exercise)
walking protocol in a thermo-neutral (+15?oC) condition (NEUTRAL),
and a cold (+5?oC), wet and windy condition (COLD). The first two
exercise periods were conducted at a higher intensity (HIGHER,
6?km.h-1 and 10% incline), than the subsequent four exercise periods
(LOWER, 5?km.h-1 and 0% incline). Rectal temperature was lower and
heart rate no different in COLD compared to NEUTRAL, while the
following were higher: oxygen consumption; respiratory exchange
ratio; plasma norepinephrine and epinephrine; blood lactate and
glucose. There was no environmental influence on these variables
during HIGHER. In conclusion, heat production during LOWER was not
sufficient to offset heat loss to the cold environment, and the
resulting reduction in rectal temperature and metabolic perturbations
may be detrimental if exercise is prolonged.
Received 16 November 1995; accepted in final form 20 June 1996.
APS Manuscript Number R719-5.
Article publication pending Am. J. Physiol. (Regulatory Integrative
Comp. Physiology).
ISSN 1080-4757 Copyright 1996 The American Physiological Society.
Published in APStracts on 4 July 96